Study On One Golf In Henan By Model Experiment And Numerical Simulation

Based on the summary of general law of gob subside,a method of Analytic Hierarchy Process(AHP)is used to rank the factors of subside caused by exploit,movement and displacement discipline of the overlying strata and the ground is studied by lab experiment according to the theory of similar,taking a gob in Henan as an prototype;numerical simulation of the prototype is conducted using MIDAS/GTS,which is followed by the research of effects of different conditions on the distribution law of the displacement of ‘ three zones 'and ground.The following shows the main work and results:(1)AHP is used to rank the importance of 11 factors affecting the subsidence of gob,including geology,circumstance and exploiting.mining degree(weight 0.3028),mining height(0.1907)are found to be the first two factors.(2)According to the theory of similar,lab experiment is conducted consisting of the design of the test apparatus,selection of affinity constant and materials,determination of mining plan and monitoring point and the record and analysis of the data.The results show that the shape of the monitoring lines of the every layer is accordant,and the settlement of each point over the gob increases with the augment of the mining progress.The displacement of monitoring points decreases as the distance to the central increases,reaching the maximum value on the center.Points closer to the gob have bigger maximum values in deep direction.The subsidence curve of the ground surface is smooth,maximum settlement point is over the center of the gob with a value of 0.451 mm,equal to 90.2 mm in the prototype model.(3)In order to verify the practicability of numerical simulation and validity of the parameters,compare between the results of experiment and simulation of the prototype by MIDAS/GTS is conducted,then different conditions are considered to research their effects on the subside law.The settlement curve is symmetry on the central axe under different conditions,points with maximum displacement appear on the central part of the gob,points far away from the goal less displacement.The settlement of the three zones varies with deep,following the order of caving zone,fracture zone and sagging zone,while it is the opposite to the region near the coal pillar.The subside settlement and degree increase with the mining width.Horizontal displacement of the ground surface increase first and decrease later from the central two sides of the gob.With the increase of mining width,points with maximum horizontal displacement move from the edge to the coal pillar.Besides,the vertical and horizontal displacements decrease as the mining depth increases,but a little increase for caving zone and fracture zone.The critical value of mining height has a big effect on the ground settlement.The effect on the ground surface and extent of mining height is not obvious,which is the same to the three zones.